New Functionality in Version 4.3

The new Transmission Line interface solves the time-harmonic transmission line equation for the electric potential. The interface is used when solving for electromagnetic wave propagation along one-dimensional transmission lines and is available in 1D, 2D, and 3D.

Mixture and Porous media models are available for both the frequency-domain and the transient RF interfaces, when specifying the relative permittivity, the relative permeability, and the conductivity. The conductivity can also be specified using Archie’s law.

New material models for specification of the relative permittivity, including dispersion, have been added to the frequency-domain Electromagnetic Waves interface:

The Drude-Lorentz model is suitable for approximating the permittivity of metals.

The Debye dispersion model describes the dielectric response of an ensemble of ideal, non-interacting dipoles.

Finally, the Sellmeier formula is widely used in optics for specification of the refractive index of optical materials as a function of the wavelength.

The different models for specifying the relative permittivity, including the new models described above, are now available also when specifying the impedance and the transition boundary condition.

PMLs are now enabled from the Definitions branch and applies PML scaling to all physics with PML support. Note: Does not apply to the Microwave Heating interface.

New far-field plots that are generated independently of the models’ mesh elements have been added. The directivity parameter is also calculated as part of the new far-field plot generator.

Default far-field plots are generated when a far-field domain feature is available in the model.

Conversion between S, Y, and Z parameter output is offered in postprocessing.

Backward Compatibility vs. Version 4.2a

Gauge Fixing Node Renamed

The Gauge Fixing node in version 4.2a has been renamed Divergence Constraint.

Backward Compatibility vs. Version 4.0a

Overridden port variables removed from solution components

Overridden port features no longer generate solution components since version 4.1. Models built in version 4.0a and 4.0 with overridden port features will display an error message when opened in version 4.1 or later. In order to successfully complete the import of such a model into version 4.3 you need to click OK to close the error message, then clear the existing solutions, and finally re-solve the model.

Java-files or M-files that create and solve COMSOL models containing overridden port features similarly need to be modified so that the code that generates the solver sequence does not refer to the removed solution components from the overridden ports.